NMR studies of nucleotide conformation and nucleotide interactions concentrated on the elucidation of structure of the associated form of guanosine-5'-phosphate at neutral pH. 13C relaxation time measurements provided limits on the size of the aggregate, while 1H spectra showed that the association is sensitive to the cations present. From dynamic NMR studies we have found that binding of Li ions to N,N-dimethylformamide increases the barrier to internal rotation by 3.5 Kcal/mole. 1H and 13C NMR studies of phospholipids and triglycerides in CDCl3 solution show the existence of an equilibrium between the two forms known from crystallographic work. BIBLIOGRAPHIC REFERENCES: NMR and Infrared Spectroscopic Studies of Hydrogen Bonding in Hindered Alcohols: An Instance of a True Hydrogen Bonded Dimer in an Alcohol. Becker, E.D., Tucker, E.E. and Rao, C.N.R., J. Chem. Soc., Faraday Trans. II 73: 438-442 (1977). Molecular Orbital Studies on the Conformation of N-Phenyl Maleimide. Govil, G. and Khetrapal, C.L., Current Science 46, 250 (1977).